How can I assign the marks with correct answer?

Hi priyasharma518, thank you for reaching us.

You may assign a calculative value for the right and wrong answers. The right answer can be assigned with value 1, while the wrong answer can be assigned with value 0.

For example, you can add single choice properties on your form then set the calculation values for the wrong and true answers as you can see the top.

You can prepare calculation values for the answers as you can see the top. Also you can examine this links for getting more information.

Related guide: How to Assign Calculation Value

Then, you may calculate the total correct question with Form Calculation.

Related guide: How to Perform Form Calculation Using a Widget

Or, you may consider utilizing our quiz app. 

Related guide: Turn Your Form into a Quiz or Exam! 

Feel free to let us know if you need any further assistance.